TY - JOUR

T1 - New approach to enhanced heat exchange efficiencies at ultralow temperatures

AU - Burton, D.

AU - Dow, R. C. M.

AU - Lambert, Colin

PY - 1986/6/1

Y1 - 1986/6/1

N2 - We examine the heat transfer between a sintered metallic powder and liquid 3He at ultralow temperatures. With the combination of a renormalization-group approach with the Lanczos method, a microscopic model is analyzed to yield the low-frequency density of states ρ(ω) of the sinter. In the weak-coupling limit ρ(ω) possesses a pronounced low-frequency peak leading to an enhanced heat transfer coefficient at low temperatures. This enhancement is shown to occur when the ratio of the long-wavelength velocity of sound Cs in the sinter to its velocity Cb in the bulk metal is small and can be optimized by minimizing this ratio.

AB - We examine the heat transfer between a sintered metallic powder and liquid 3He at ultralow temperatures. With the combination of a renormalization-group approach with the Lanczos method, a microscopic model is analyzed to yield the low-frequency density of states ρ(ω) of the sinter. In the weak-coupling limit ρ(ω) possesses a pronounced low-frequency peak leading to an enhanced heat transfer coefficient at low temperatures. This enhancement is shown to occur when the ratio of the long-wavelength velocity of sound Cs in the sinter to its velocity Cb in the bulk metal is small and can be optimized by minimizing this ratio.

U2 - 10.1103/PhysRevB.33.7803

DO - 10.1103/PhysRevB.33.7803

M3 - Comment/debate

VL - 33

SP - 7803

EP - 7805

JO - Physical review B

JF - Physical review B

SN - 0163-1829

IS - 11

ER -